This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. ACBT spheroids following acute, chronic, and repetitive PDT will be imaged for live-dead assays and apoptosis. The therapeutic usefulness of gene therapy is often limited by an inefficient transfer of the macromolecule into the cytosol, and a lack of site-specific targeting. Photochemical internalization (PCI) is based on photochemically induced release of endocytosed macromolecules from endosomes and lysosomes into the cytosol. PCI has been used in combination with gene therapy and has been shown to increase gene gene expression. The ability of PCI to enhance the gene insertion of the tumor suppressor gene PAX6 or reporter genes into glioma cells will be studied in vivo and in vitro. Monolayer and multicellular spheroid cultures of the rat glioma cell lines F98 and RG2 will be used in the in vitro studies. The same cell lines will be used to induce intracranial tumors in rats. Confocal and multi photon fluorescence microscopy will be used to study photosensitizer distribution, expression of reporter gene (GFP), and cell survival.